Canvas slat



A. TOWNS.

CANVAS SLAT. APPLICATION FILED JUNE 3,1919.

Patented Dec. 21,1920

j amend/cop JfLflwma PATENT OFFICE.

ALBERT TOWNS, OF OTTERTAIL, MINNESOTA.

CANVAS SLAT.

Specification of Letters Patent.

Patented Dec. 21, 1920.

Application filed June 3, 1919. Serial No. 301,431.

To all whom it may concern:

Be it known that I, ALBERT TowNs, a citizen of the United States,residing at Ottertail, in the county of Otter Tail, State of Minnesota,have invented certain new and useful Improvements in Canvas Slats; and Ido hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention relates to slats for conveycr aprons, and it has for itsobject to provide an improved means for providing a slat on theconveyer, in which the fabric of the conveyer will not be subjected tosharp bends such as serve to injure the fab-- ric in use. It is, ofcourse, understood that the cotton fabric or canvas of which theconveyer apron is ordinarily made, may be broken by repeated reversebending of it, as is the fabric in a pneumatic tire that is uninflated.

It is the object of the present invention to so build the completearticle that when positioned upon the belt, the bendin of the belt willbe around a comparatively road curvature.

Reference is had to the accompanying drawings forming a part of thisapplication, wherein like reference characters re fer to similar partsthroughout the several views, in which- Figure 1 is a perspective viewshowing a canvas carrier or apron provided with an improved form of slatconstructed in accordance with the invention.

Fig. 2 is an enlarged sectional view thereof taken transversely, and

Fig. 3 is a longitudinal section.

Referring to the drawings in detail, the numeral 10 designates a canvascarrier or apron preferably of the endless type upon which ordinarilywooden slats are arranged and secured transversely at spaced intervalsto constitute carrier means, as particularly adapted for use inconnection with binders, threshing machines or the like. In lieu ofemploying such ordinary wooden slats, the present invention contemplatesthe use of a slat designated at 11, composed of a .tube or other memberof circular cross I section, preferably a hollow steel tube which ismade relatively light. This tube is of the same length as the width ofthe carrier and is disposed so as to be enveloped by a portion of thecanvas, in the manner shown It will be observed from the drawings thatthe portion 12 of the canvas substantially envelops the tube forming theslat 11, leaving a narrow neck or throat portion 13 uncovered. However,since the major portion of the circumference of the tube is enveloped bythe canvas, the tube may be retained in position by means of a sheet orspring metal case or retainer 14 engaged on the slat or tube outwardlyof the canvas in the manner clearly shown in the drawings. This case ismade of a section of sheet metal or spring steel and rolled into theform of a longitudinally split cylindrical tube so that the meetingedges 15 thereof will then spring together when released from the slat.These edges 15 are turned backwardly or rolled as indicated at 16 soloss of grain will be prevented and as the device is very light, and canbe readily assembled or disassembled for repair, replacement or forvarying the spaced relation of the slats, it will be seen that thedevice possesses a marked advantage over the old construction. It shouldalso be noted that the case or retainer fits snugly on the canvasenveloping the tube forming the slat, thus retaining the parts againstdisplacement. Furthermore, one end of the tube is rounded or reduced insize as shown at 18, so as to facilitate its attachment by preventingthe end thereof from catching in the canvas.

It will be understood, of course, that it is the side of the apronopposite to the slat that engages around the drive and carrying rollers.As the apron moves, it has a slight up and down waving motion whichcauses a back and forth bending movement of the apron about thecylindrically rolled edge portion 16 of the case 14, and by reason ofthe wide curvatures of these portions 16, the bending is gradual and notabrupt, so that the canvas does not crack as it would do were it not forthe cylindrical beads 16.

This bending takes place in one direction also as the belt passes ontothe roller and takes place in an opposite direction asthe belt incasesthe cylindrical tube 11 for an angular distance of approximately 300degrees, which is the approximate angular extent of the casing 14 sothat the parts are held securely in proper positions.

It will furthermore, of course, be under stood that when the canvas ofthe apron is tensioned around-the slat 11, the curvingly reduced endportions 18 will permit the margins of the apron to draw slightlyinwardly over such curvatures and thus hold the slat securely againstlongitudinal dis placement. It will furthermore be noted that theuncovered portion 13 of the slat 11 is so broad that the slat is heldagainst ex cessive rocking with respect to the apron. Excessive rockingwith considerable ampli tude, of course, deteriorates the fiber of thecanvas apron so that the apron tends to break Where it leaves theretainer. With the vibrations and the amplitude of the vibrationsreduced, the life of the apron is correspondingly prolonged.

What is claimed is:

The combination with a canvas conveyer apron of a cylindrical tubular'slat incased partway of its circumference by the canvas with its endsterminating in planes includ ing the marginal edges of the canvasywhichends of the slat are curvingly reduced, and a resilientlongitudinallysplittube between which and the slat the incasing portion of the canvasis gripped and which split tube extends from edge to edge of the canvas,the split tube having an angular extent of substantially 270 degrees andhaving its material at each side of the split directed away from thesplit in the form of a cylindrical bead, partway about which the canvasis bent and extended in opposite directions away from the slat.

In testimonywhereof I aflix my signature in the presence of twowitnesses. V ALBERT TOWNS.

\Vitnesses:

FRED. B. PETERSON, E; W, 'FRANcIs.

